center of the diagram over Gananoque, following instructions in each of
these cases with reference to the direction lines to be drawn. The result
was that the intersection of the three lines was at approximately the
point indicated by the Rockport amateur.

"Now we're ready to continue our search," Cub announced.

"That's pretty good progress, I must say," Bud declared; "but here's a
new question to get us into trouble again."

"Oh, for goodness sake, don't," pleaded Cub. "You've had your example of
what my mathematical dad can do with such foolish creatures."

"Let him express his doubt," suggested Mr. Perry with a smile; "for,
if a man must doubt, he'd better shout than smother his ideas in a
skeptic pout."

"Yes, get it off your chest, Bud, and then take your medicine,"
advised Hal.

"Well, suppose we find the island and nobody there, how are we going to
know it's the right one?"

This hit the other two boys pretty hard. The possibility of such a
situation had not occurred to either of them. However, Cub preferred to
take it in lighter vein, for he replied:

"By his footprints on the sandy beach. You mustn't have a Crusoe Island
without some footprints, you know."